Metals and Their Reactions – Quick Revision

Periodic Table & Metal Properties

• Elements arranged in vertical groups and horizontal periods

• Metals: left & middle of table; properties

  • Shiny, high melting point/density, good conductors, malleable

• Key terms

  • Conductor: allows heat/electricity flow

  • Malleable: changes shape when hammered

Reactivity Series (most ➔ least)

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• $\text{K, Na, Ca, Mg, Al, Zn, Fe, Cu, Ag, Au}$

• Mnemonic: “Please Send Charlie’s Monkeys And Zebras In Large Cages Securely Guarded”

Metal Reactions

• With acids: $\text{acid + metal} \to \text{salt + }H_2$ (test: lit splint → squeaky pop)

  • Salt ending depends on acid

  • HCl → chloride, $H<em>2SO</em>4$ → sulfate, $HNO_3$ → nitrate

  • Eg. $\text{Mg + 2HCl} \to \text{MgCl}<em>2 + H</em>2$

• With oxygen: $\text{metal + O}_2 \to \text{metal oxide}$

  • Eg. $2\text{Mg} + O_2 \to 2\text{MgO}$

• With water (very reactive metals): $\text{metal + H}<em>2O \to \text{metal hydroxide + }H</em>2$

  • Alkali formed; UI turns blue-purple

  • Eg. $2\text{Na} + 2H<em>2O \to 2\text{NaOH} + H</em>2$

Displacement Reactions (HT)

• More reactive metal replaces less reactive metal in compound

  • Eg. $\text{CuSO}<em>4 + Zn \to \text{ZnSO}</em>4 + Cu$

• No reaction if incoming metal is less reactive (e.g. Zn with MgSO₄)

Extraction with Carbon

• Metals less reactive than carbon reduced from oxides by heating with C

  • Eg. $\text{2CuO} + C \to 2Cu + CO_2$

• Ore: rock containing metal oxide suitable for extraction

Equations & Balancing

• Word, symbol, and balanced forms required

• Balance by adjusting coefficients only

  • $\text{Mg + O}<em>2 \to \text{MgO}$ → $2\text{Mg} + O</em>2 \to 2\text{MgO}$

  • $\text{Zn + HCl} \to \text{ZnCl}<em>2 + H</em>2$ → $\text{Zn} + 2HCl \to \text{ZnCl}<em>2 + H</em>2$

Practical Planning

• Compare metal reactivity using copper chloride solution

• Consider: warming $H<em>2SO</em>4$ for faster CuSO₄ formation; use excess acid to ensure complete reaction

Variables

• Independent: changed (e.g. type of metal)

• Dependent: measured (e.g. temperature rise)

• Control: kept constant (volume & concentration of $\text{CuCl}_2$, starting temp, metal mass)

Key Definitions

• Group / Period: vertical / horizontal classifications in periodic table

• Hydrogen gas: $H_2$

• Reactivity series: ordered list of metal reactivity

• Displacement reaction: more reactive metal takes place of less reactive one

• Independent / Dependent / Control variables: experiment factors to change, measure, keep constant